Host-Microbe Immune Response Flashcards
When are there deficiencies or impaired function of phagocytes?
Haematological malignancy
Cytotoxic chemo
What does T-cell deficiency cause susceptibility to?
Viruses, fungi, mycobacteria and parasites (mostly intracellular organisms).
When do you get a T-cell deficiency?
HIV
Lymphoma
Primary immunodeficiency syndromes e.g. SCID
When do you get B-cell deficiency?
Myeloma (paraproteinaemia with immune paresis)
Primary immunodeficiency syndromes
Certain immune suppressants e.g. rituximab
What do people with HIV have increased risk of regardless of CD4 count?
Invasive pneumococcal (s. pneumoniae) disease e.g. bacteraemia, meningitis, empyema.
Who does toxoplasma gondii affect and what does this cause?
People with HIV
Cerebral abscesses
What causes functional hyposplenism?
Sickle cell anaemia
Cirrhosis
Coeliac disease
What does hyposplenism increase susceptibility to?
Encapsulated organisms e.g. strep pneumoniae, Hib, neisseria meningitidis (meningococcus)
What can be done to reduce the risks of hyposplenism?
Vaccination (preferably before splenectomy).
What abnormal signs of infection may immunosuppressed people show?
Absent fever
No inflammatory response (no CRP or neutrophilia)
Non-specifically unwell with no localising features
What infections are steroids associated with?
Wide range but particularly fungi
What infections is anti-TNFalpha treatment associated with?
TB
Fungal infections esp aspergillus
What infections are purine analogues associated with (chemo used in haematological malignancy)?
Viral infections esp HSV and HZV
Pneumocystis jirovecii
Why is co-trim sometimes used prophylactically in patients with HIV?
To try and prevent PJP
What would you use as prophylaxis in a bone marrow transplant recipient?
Antifungal agent e.g. intraconazole
